Cancer is often a deadly disease. In the United States, for instance, cancer is the second leading cause of death after heart disease and accounts for about 526,000 deaths annually. One of three Americans develops cancer and one of four Americans dies of cancer. The number of deaths attributed to cancer is rising, because of a combination of a growing elderly population and a decline in deaths from heart disease.
Cancer may be detected in several ways. In a biopsy, for instance, tissue suspected of being cancerous is removed and tested for malignancy. For routine screening purposes, however, biopsies are undesirable, because (i) the cancer has to have progressed sufficiently so that a tissue sample is available, and (ii) the tests and equipment to conduct the biopsies are expensive and time-consuming. Moreover, biopsies may metastatically spread the cancer through blood and/or tissue droplets. There is a need to develop a cancer detection screening test which is effective, inexpensive, and easily performed.
It has now been unexpectedly discovered that the levels of certain acids in a mammal change when the mammal has developed a cancerous condition or a pre-cancerous condition.
As used in this application, a "cancerous condition" is a condition in which a mammal's immune system has failed to recognize and destroy malignant cells. A "pre-cancerous condition" is a condition which has been reported as potentially developing into a cancerous condition.
It is an object of this invention to develop a method for determining whether a mammal should be medically investigated for a cancerous condition.
It is a further object of this invention to develop a method that determines whether a mammal should be medically investigated for a pre-cancerous condition.
It is a further object of this invention to develop a simple, relatively inexpensive screening technique which can be easily performed and is likely to identify early stages of a cancer's development.
It is a further object of this invention to develop a non-invasive cancer detection method that does not carry the risk of metastatic spread of cancer via blood and/or tissue droplets.
These and still further objects will be apparent from the following description of this invention.